I have upgraded my MC iPhone 3GS to OS4.0 but found very quicky that there is no jailbreak for this combination. Is there any way to restore 3.1.3 so I can go back to JB with the MC model or am I screwed until someone breaks 4.0?

I have been looking around on this site and others for a while to see if I can downgrade a 3GS from iOS4 that I may buy from a friend. He never had the phone jailbroken or unlocked but he recently upgraded to iOS4 so I wanted to make sure that it's impossible now to perform any type of jailbreak. Can anyone confirm that for me?

I have a mb version 3GS it has 4.0 and has never been jailbroken, how can I jail break??

I believe that's the same boat I'm in, I am 99% sure I'm going to buy a friends 3GS for $140 but it's never been jailbroken and is currently on 4.0. Worst case I can resell the phone for the same price but it would be nice to know what I can do.

Hi guys i accidently upgraded to 4.0fw
i have iphone 3gs
mc model i.e. new boot rom
i was previously on 3.1.3 firmware where i used spirit to jail break also i did save me 3.1.3 SHSH blobs but NOT 3.1.2 CAUSE MY IPHONE 3GS CAME WITH 3.1.3 pre-installed

q1) would i be able to jailbreak/unlock if so how.
q2)would i be able to downgrade to 3.1.3 or 3.1.2 then jailbreak/unloack again if so how

Point your hosts file to the Cydia Server where your 3.1.2 SHSH blobs are stored.

Restore to 3.1.2 EVEN IF you are on 4.0 official.

Run Blackra1n to jailbreak 3.1.2.

Now you are jailbroken again, simply upgrade to a Pwned 4.0 FW.

I JUST DID IT, it works PERFECTLY. I was on unpwned 4.0 official from where I upgraded last night

No matter how many times I do this or what I try, it does not work. It won't even let me upgrade to 4.0. It is like it doesn't like the hosts entry (Windows XP) and it just bombs and fails. Is there some other trick? Do I need to turn off my firewall or reboot the laptop or something?

Originally Posted by adriancombe

No matter how many times I do this or what I try, it does not work. It won't even let me upgrade to 4.0. It is like it doesn't like the hosts entry (Windows XP) and it just bombs and fails. Is there some other trick? Do I need to turn off my firewall or reboot the laptop or something?

Actually someone online had a page that taught me to flush the dns cache and I think I may be good now, will advise. Many thanks.

Hey guys, my 3gs is currently on 3.0 firmware, jailbreak and unlock. Would like to update to 4.0 firmware, jailbreak and unlock. Will sn0wbreeze work for me or do I need to be at 3.1.2 firmware for it to work??? Thanks in advance

No matter how many times I do this or what I try, it does not work. It won't even let me upgrade to 4.0. It is like it doesn't like the hosts entry (Windows XP) and it just bombs and fails. Is there some other trick? Do I need to turn off my firewall or reboot the laptop or something?

Actually someone online had a page that taught me to flush the dns cache and I think I may be good now, will advise. Many thanks.

Darn, I am not good to go. It gets all the way to the end of the white line on the black iphone screen (further than before) and THEN it fails in Itunes and I am stuck in recovery mode...help...

Originally Posted by one1

No matter what Firmware you are on, even 4.0 official, just go to the MMI downloads section and get

Point your hosts file to the Cydia Server where your 3.1.2 SHSH blobs are stored.

Restore to 3.1.2 EVEN IF you are on 4.0 official.

Run Blackra1n to jailbreak 3.1.2.

Now you are jailbroken again, simply upgrade to a Pwned 4.0 FW.

I JUST DID IT, it works PERFECTLY. I was on unpwned 4.0 official from where I upgraded last night

Ok, so I FINALLY got it go back to 3.1.2 and jailbroke it with blackrain just like you said (THANKS!)

BUT, now I cannot understand the last step, "upgrade to a Pwned 4.0 FW" Is there somewhere I can download this firmware? I went through an arduous process with snowbreeze extracting and recreating its own 4.0 firmware only to have I tunes give me a 1600 error and fail when I tried to restore with it...

It was jailbroken and unlocked under 3.1.3 but I unfortunatelly upgrade to 4.0 I succesfully downgrade to 3.1.3 but is unjailbreakable with nothing. Have you any hint? I am very disappointed with this Crapple. I should buy some open system like Android, I believe!

I have an iphone 3gs on 4.0. I just bought it from someone and I don't think it has ever been jailbroken/unlocked. Would this procedure work to be able to downgrade to 3.1.2 even if i don't have any shs blobs saved????